The earliest known Chinese snuff bottles were made of brass, between 1646 and 1653, during the Shun Zhi period (1644-1661). It is said that when Emperor Kang Xi (1654-1722) celebrated his sixtieth birthday he was given two bottles of snuff by Jesuit missionaries. By the Qing Long period, a number of enameled snuff bottles were produced for the use of the imperial household. On the bottom are incised marks filled with blue enamel indicating the reign during which they were manufactured. Today these bottles are considered the finest and rarest specimens.